Arsenic Body Burden Research Articles

Historical exposure to metals in contaminated areas and its impact on cardio- and cerebrovascular health

Environmental pollution is of global concern. In Southeast Sweden, historical glass production has contaminated communities with toxic metals. Long-term residency in these communities and high consumption of local foods may constitute a risk for cardiovascular disease (CVD) or stroke.The current study investigates if residency in these contaminated sites and long-term consumption of local foods is associated with self-reported CVD and stroke. In addition, the body burden of the toxic metals arsenic, cadmium, and lead, as well as inflammatory protein markers, were studied for association with CVD and stroke.From an existing questionnaire cohort and biomonitoring sub cohort (n = 2290/882) of people living in the contaminated areas, self-reported CVD cases (n = 366/166) and stroke cases (n = 78/25) were identified. Individuals were grouped based on their residency within a 2 km radius of glassworks with historical high, moderate, or low air-borne lead emissions. Body burden of arsenic, cadmium, and lead was analyzed using ICP-MS. Inflammatory markers were investigated using electrochemiluminescence.Long-term residency near glassworks with historically high levels of lead emissions, and high consumption of local foods, were associated with CVD. The risk was increasing for each year of residency in high emission areas. Increased body burden of arsenic in blood, and lead in urine, were associated with stroke. Five and two inflammatory markers, respectively, were elevated in CVD and stroke cases after adjusting for confounders.An increased risk for CVD was found in areas with historically high emissions of lead but possibly also other toxic metals. Interestingly, there was an indication of a dose-response relationship with increasing risk for CVD per year of residency time. Inhalation and consumption of local food may constitute major pathways for this association. The study shows that long-term exposure to toxic metals in these contaminated areas is associated with CVD and that there is a need to limit exposure in the general population.

Health effects and metabolic pathway of arsenic in children

Our six years of field experience in Bangladesh showed that normally children under 11 years of age do not show arsenical skin manifestations. However, we have observed a few exceptions when (1) the arsenic content in water consumed by children is very high (≥1,000 µg/L) and (2) the arsenic content is not very high, but the children get poor nutrition. It appears that although 6.12% of 4,864 children showed arsenic skin lesions but hair and nail analysis of children (below 11 years) with or without arsenical skin lesions from affected villages of Bangladesh showed that 84% of the children had arsenic in hair more than the toxic level and 89% in nail above normal level. It appears that children living in arsenic affected villages have higher arsenic body burden but less dermatological symptoms. The value of arsenic excretion and arsenic intake per kg of body weight ratio for adults is 0.53 while that of the children is 0.69. This indicates total arsenic excretion is higher for children per kg of body weight than adults. The average values (n = 18) for speciation of arsenic in children urine are 15.60% In-As, 10.64% MMA, and 73.76% DMA. Overall percentage of MMA is higher, and DMA is lower in adults than children (average % MMA is 17.20 vs. 10.64 and % DMA is 64.62 vs. 73.76%, respectively). Therefore, the 2nd methylation step (MMA to DMA) could be more active in children than adults. The results indicate that the first reaction of the metabolism pathway is more active in adults than children, basically in adult’s male. Also shows a significant (t-test positive) increase in the values of the DMA/MMA ratio in children compared to adults of the exposed group (8.15 vs. 4.11, respectively). Moreover, it is also observed that the second methylation step in the arsenic metabolic pathway is more active in children than adults. Because there is no significant difference of the values of MMA/iAs ratio, but the values of DMA/MMA ratio are significantly different between adults and children of the exposed group (0.92 vs. 0.73 for MMA/Asi and 4.11 vs 8.15 for DMA/MMA, respectively). Thus, from these results we may conclude that children retain arsenic shorter in their body comparing adults.

Discovering Efficient Method Extracting Arsenic from Human Milk Samples

In this article, the arsenic levels in drinking water were investigated. Hair and nail arsenic is strongly related, however, according to principal component analysis (PCA). According to our findings, lactating women with hypertension higher levels. Arsenic levels in infants' blood, nails, and urine were examined, and the findings indicated a substantially high body burden of arsenic in regions. The hair and nail arsenic levels were shown to be age-dependent utilizing PCA. The methods for extracting arsenic from human milk samples are effective in both literatures. These results would help in the development of a faster and more efficient technique for removing arsenic from milk samples. Although the procedure will take longer than anticipated, it does not exceed 5-6 hours. Furthermore, such studies reveal the degree of arsenic exposure in individuals living in complicated settings. People are exposed to less arsenic as a result of this, which may lead to severe cases of chronic arsenic poisoning. Prenatal exposure to babies may possibly cause genetic abnormalities as well as physical and mental problems.

Food Chain Arsenic: Additional body burden on health of arsenic

Introduction
 
 
 Arsenic: The king of poisons, the poisons of kings, and the bane of investigators1. The IARC2 has classified arsenic as a group 1 human carcinogen. Chronic exposure to inorganic arsenic can cause cancerous2-5 and non-cancerous health hazards6,7 in humans. Arsenic can get entry into the human body via drinking water, eating food, inhaling dust, and/or ingesting soil.
 
 In arsenic affected areas of West Bengal-India and Bangladesh huge quantity of arsenic is falling on agricultural land. A study in West Bengal-India reported that in a 201 km2 area of the Deganga block in the arsenic-affected district of North 24-Parganas, 6.4 tons of arsenic is falling on agricultural land in one year from 3200 contaminated tube wells for agricultural irrigation8. They expect tons of arsenic is coming with underground water in the arsenic affected areas of West Bengal-India and Bangladesh and falling on irrigated land. Thus, it is expected arsenic is entering the food chain.
 
 
 
 
 
 Figure. Using tube well water for agricultural irrigation.
 
 Rice and vegetable are the staple food for poor villagers of West Bengal, India and Bangladesh. This is true for the villagers in Kolsur gram-panchayet (G.P.) in Deganga block of North 24-Parganas district, West Bengal-India, where a group of researchers studied for arsenic in soil, rice, and vegetables from fields cultivated with arsenic contaminated water. From the results of total arsenic (drinking water + rice + vegetables + Pantavat + water added for food preparation) body burden to North Kolsur villagers [1185.0 µg for per adult per day and 653.2 µg for per child (around 10 years) per day], as the amount of arsenic coming from rice, vegetables, and water added for Pantavat and food preparation is 485 µg i.e., 41% of total for adult and 253.2 µg i.e., 38.8% for child and from rice and vegetable 285 µg i.e., 24% of total for adult and 153.2 µg i.e., 23.4% for child9-11. Their findings show most of the arsenic coming from food is inorganic in nature10. They reported that 95% and 5% of the arsenic are inorganic arsenic and methylated arsenic in rice, and 96% and 4% are inorganic arsenic and methylated arsenic in vegetables, respectively10.
 
 According to WHO12 1.0 µg of inorganic arsenic per day may give rise to skin effects within a few years.
 It has been estimated that based upon the current U.S. Environmental Protection Agency (EPA) standard of 50 µg/L, the lifetime risk of dying from cancer of the liver, lung, kidney, or bladder, from drinking 1 liter per day of water could be as high as 13 per 1000 persons13. Using the same methods, the risk estimate for 500 µgL of arsenic in drinking water would be 13 per 100 persons14. In its latest document on arsenic in drinking water, the U.S. National Research Council (NRC) concluded that exposure to 50 µg/L could easily result in a combined cancer risk15 of 1 in 100. Comparing to the WHO, EPA, and NRC document with arsenic burden to Kolsur villagers from water and food it appears that Kolsur villagers’ risk of suffering from arsenical skin effect and cancer is there. Compared to worldwide arsenic consumption from food, it appears Kolsur villagers are also consuming high amount of inorganic arsenic from food and vegetables. Kolsur village is an example of many such villages in West Bengal-India and Bangladesh.
 Furthermore, products from arsenic irrigated water- soil system rich in arsenic are also coming to common marketplace far away from contaminated areas and even people who are not drinking arsenic contaminated water may get arsenic from food products produced from contaminated fields. In West Bengal-India and Bangladesh rice, vegetables, and other products are coming to cities (including Kolkata in West Bengal-India and Dhaka in Bangladesh) from villages and possibility that city people consuming arsenic contaminated products from contaminated areas cannot be ruled out.

Public Health and Paediatric Risk Assessment of Aluminium, Arsenic and Mercury in Infant Formulas Marketed in Nigeria.

ObjectivesInfant formulas are useful alternatives to breast milk in many circumstances but may pose health risks to infants and children due to contamination by potentially toxic metals. This study aimed to determine the aluminium, arsenic and mercury concentrations and carry out an exposure health risk assessment in commonly consumed infant formulas in Nigeria.MethodsDifferent brands of both locally manufactured and imported infant formulas were purchased in March 2017 from stores in Port Harcourt, Nigeria. Analysis of metals in the samples was performed by atomic absorption spectrophotometry. The health risk was assessed by comparing estimated daily intake of aluminium, arsenic and mercury with the provisional tolerable daily intake acceptable by the Joint Food and Agricultural Organization/World Health Organization Expert Committee on Food Additives (JECFA).ResultsA total of 26 infant formulas were analysed. The levels of arsenic were higher in cereal-based formulas compared to milk-based formulas, but the difference was not significant (P >0.05). The intake levels of aluminium, arsenic and mercury in infant formulas were found to be 8.02–14.2%, 437.1–771% and 23.7–41.8% of the provisional tolerable daily intake JECFA threshold values, respectively.ConclusionCommonly consumed infant formulas in Nigeria may add to the body burden of arsenic in children.

Groundwater arsenic contamination in Bangladesh—21 Years of research

Department of Public Health Engineering (DPHE), Bangladesh first identified their groundwater arsenic contamination in 1993. But before the international arsenic conference in Dhaka in February 1998, the problem was not widely accepted. Even in the international arsenic conference in West-Bengal, India in February, 1995, representatives of international agencies in Bangladesh and Bangladesh government attended the conference but they denied the groundwater arsenic contamination in Bangladesh. School of Environmental Studies (SOES), Jadavpur University, Kolkata, India first identified arsenic patient in Bangladesh in 1992 and informed WHO, UNICEF of Bangladesh and Govt. of Bangladesh from April 1994 to August 1995. British Geological Survey (BGS) dug hand tube-wells in Bangladesh in 1980s and early 1990s but they did not test the water for arsenic. Again BGS came back to Bangladesh in 1992 to assess the quality of the water of the tube-wells they installed but they still did not test for arsenic when groundwater arsenic contamination and its health effects in West Bengal in Bengal delta was already published in WHO Bulletin in 1988. From December 1996, SOES in collaboration with Dhaka Community Hospital (DCH), Bangladesh started analyzing hand tube-wells for arsenic from all 64 districts in four geomorphologic regions of Bangladesh. So far over 54,000 tube-well water samples had been analyzed by flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS). From SOES water analysis data at present we could assess status of arsenic groundwater contamination in four geo-morphological regions of Bangladesh and location of possible arsenic safe groundwater. SOES and DCH also made some preliminary work with their medical team to identify patients suffering from arsenic related diseases. SOES further analyzed few thousands biological samples (hair, nail, urine and skin scales) and foodstuffs for arsenic to know arsenic body burden and people sub-clinically affected. SOES and DCH made a few follow-up studies in some districts to know their overall situations after 9 to 18 years of their first exposure. The overall conclusion from these follow-up studies is (a) villagers are now more aware about the danger of drinking arsenic contaminated water (b) villagers are currently drinking less arsenic contaminated water (c) many villagers in affected village died of cancer (d) arsenic contaminated water is in use for agricultural irrigation and arsenic exposure from food chain could be future danger. Since at present more information is coming about health effects from low arsenic exposure, Bangladesh Government should immediately focus on their huge surface water management and reduce their permissible limit of arsenic in drinking water.

Geostatistical modelling of arsenic in drinking water wells and related toenail arsenic concentrations across Nova Scotia, Canada

Arsenic is a naturally occurring class 1 human carcinogen that is widespread in private drinking water wells throughout the province of Nova Scotia in Canada. In this paper we explore the spatial variation in toenail arsenic concentrations (arsenic body burden) in Nova Scotia. We describe the regional distribution of arsenic concentrations in private well water supplies in the province, and evaluate the geological and environmental features associated with higher levels of arsenic in well water. We develop geostatistical process models to predict high toenail arsenic concentrations and high well water arsenic concentrations, which have utility for studies where no direct measurements of arsenic body burden or arsenic exposure are available. 892 men and women who participated in the Atlantic Partnership for Tomorrow's Health Project provided both drinking water and toenail clipping samples. Information on socio-demographic, lifestyle and health factors was obtained with a set of standardized questionnaires. Anthropometric indices and arsenic concentrations in drinking water and toenails were measured. In addition, data on arsenic concentrations in 10,498 private wells were provided by the Nova Scotia Department of Environment. We utilised stepwise multivariable logistic regression modelling to develop separate statistical models to: a) predict high toenail arsenic concentrations (defined as toenail arsenic levels ≥0.12μgg−1) and b) predict high well water arsenic concentrations (defined as well water arsenic levels ≥5.0μgL−1). We found that the geological and environmental information that predicted well water arsenic concentrations can also be used to accurately predict toenail arsenic concentrations. We conclude that geological and environmental factors contributing to arsenic contamination in well water are the major contributing influences on arsenic body burden among Nova Scotia residents. Further studies are warranted to assess appropriate intervention strategies for reducing arsenic body burden among human populations.

What is the role of obesity in the aetiology of arsenic-related disease?

Consumption of arsenic contaminated drinking water causes a large variety of adverse health outcomes. Body mass index (BMI), which is linked to diet, is positively associated with arsenic methylation capacity. We investigated the association between an obesity-related diet and arsenic body burden from exposure to naturally contaminated drinking water among Nova Scotia residents. We collected home drinking water and toenail clipping samples among 960 men and women aged 35 to 69years in Nova Scotia, Canada from 2009 through 2010. We measured body composition and arsenic concentrations in drinking water and toenails clipping samples and collected socio-demographic, behavioural, and dietary information via standardized questionnaires. We derived an obesity-related dietary pattern score using reduced rank regression. Across quartiles of the obesity-related dietary pattern score there were no significant differences in drinking water arsenic concentrations, but there was an inverse trend in arsenic concentrations in toenails across the dietary pattern score (P=0.01). Compared with individuals in the first quartile of the dietary pattern score, those in the second through fourth quartiles had decreased likelihoods of high toenail arsenic (≥85 percentile). The corresponding odds ratios (95% confidence intervals [CI]) were 0.81 (95% CI, 0.49, 1.36), 0.57 (95% CI, 0.33, 0.99), and 0.55 (95% CI, 0.31, 0.98), respectively (P for trend=0.02). We conclude that given similar levels of naturally occurring arsenic exposure via drinking water, an obesity-related dietary pattern was associated with significantly lower arsenic concentrations in toenails. Further studies to investigate the underlining mechanisms are warranted.

Relationship between drinking water and toenail arsenic concentrations among a cohort of Nova Scotians

Consumption of arsenic-contaminated drinking water is associated with increased cancer risk. The relationship between arsenic body burden, such as concentrations in human toenails, and arsenic in drinking water is not fully understood. We evaluated the relationship between arsenic concentrations in drinking water and toenail clippings among a cohort of Nova Scotians. A total of 960 men and women aged 35 to 69 years provided home drinking water and toenail clipping samples. Information on water source and treatment use and covariables was collected through questionnaires. Arsenic concentrations in drinking water and toenail clippings and anthropometric indices were measured. Private drilled water wells had higher arsenic concentrations compared with other dug wells and municipal drinking water sources (P<0.001). Among participants with drinking water arsenic levels ≥1 μg/l, there was a significant relationship between drinking water and toenail arsenic concentrations (r=0.46, P<0.0001). Given similar levels of arsenic exposure from drinking water, obese individuals had significantly lower concentrations of arsenic in toenails compared with those with a normal weight. Private drilled water wells were an important source of arsenic exposure in the study population. Body weight modifies the relationship between drinking water arsenic exposure and toenail arsenic concentrations.

Improved Sustainability of Water Supply Options in Areas with Arsenic-Impacted Groundwater

The supply of water for rural populations in developing countries continues to present enormous problems, particularly where there is arsenic contamination in the groundwater, as exists over significant parts of Bangladesh. In response, improvements in the sustainability of water supplies are feasible through the use of a combination of water sources wherein rainwater harvesting is employed for a portion of the year. This can potentially reduce the duration of the year during which arsenic-contaminated groundwater is utilized. As demonstrated, a rainwater cistern volume of 0.5 m3 in the Jessore district area of Bangladesh can provide rainwater for periods averaging 266 days of the year, which allows groundwater at 184 µg/L arsenic to be used as a water supply for the remainder of the year. This dual supply approach provides the body burden equivalent to the interim drinking water guideline of arsenic concentration of 50 µg/L for 365 days of the year (assuming the water consumption rate is 4 L/cap/day for a family of five with a rainwater collection area of 15 m2). If the water use rate is 20 L/cap/day, the same cistern can provide water for 150 days of the year; however, although this is insufficient to supply water to meet the body burden equivalent guideline of 50 µg/L. Results are provided also for different rooftop areas, sizes of cisterns and alternative arsenic guidelines [World Health Organization (WHO) and Bangladeshi]. These findings provide useful guidelines on supply options to meet sustainability targets of water supply. However, they also demonstrate that the use of cisterns cannot assist the meeting of the 10 µg/L WHO target arsenic body burden, if the arsenic contamination in the groundwater is high (e.g., at 100 µg/L).

Changes in body burden of mercury, lead, arsenic, cadmium and selenium in infants during early lactation in comparison with placental transfer

The developing brains of both fetuses and infants are susceptible to environmental contaminants. However, the contribution of breast-feeding to the element body burden in infants remains unclear. The main objective of this study was to investigate the changes in body burden of elements such as methylmercury, lead, arsenic, cadmium, and selenium in infants during a 3-month breast-feeding period compared with placental transfer of the elements. Element concentrations were measured in maternal and umbilical cord (fetus) red blood cells (RBCs) at parturition and in infant RBCs at 3 months. Most of the mercury in RBCs is in the methyl form, and the total mercury concentration in RBCs reflects methylmercury exposure. The mercury level in cord RBCs was approximately 1.5 times higher than that in mothers, while in infants, it declined by approximately 60% after 3-months' breast-feeding. The cord selenium level was similar to the maternal level, but declined approximately 75% after 3-months' breast-feeding in infants. Lead and arsenic concentrations in cord RBCs were about 60% of the maternal levels, and remained constant until the 3-month study period. The cadmium level in cord RBCs was about 20% of that in maternal RBCs, and remained almost constant until the end of the 3-month study period. In conclusion, although pregnant women should pay attention to avoid high methylmercury exposure, element exposure through breast-feeding does not pose any great concern in this population.

Survival, reproduction, and arsenic body burdens in Chironomus riparius exposed to arsenate and phosphate

Despite the increasing awareness of arsenic (As) contamination in surface waters worldwide, little is known about how As alone and in the presence of other chemicals affects aquatic insects. Larvae of Chironomus riparius were exposed in a laboratory investigation to factorial combinations of 0, 0.13, 2.0, 5.3, and 13μmolAsl−1 and 0, 0.15, and 15μmolPO4l−1 throughout development from first instar to pupal emergence. The time between male and female emergence increased from 1.8±0.17days to 2.9±0.34days with exposure at higher As levels. The highest As exposure also decreased the number of eggs per egg mass, which may affect population maintenance. For these parameters, there was no effect from PO4, and no interaction between As and PO4. Total As determination of larval and adult tissues was conducted using Hydride Generated Atomic Absorption Spectroscopy (HGAAS) and revealed concentrations ranging from 2.48±0.363 to 30.5±0.473μg/g and 1.03±0.286 to 8.97±0.662μg/g, respectively, indicating elimination of approximately 72% of total As body burdens between the fourth instar and adult stages. There was no effect of PO4, indicating PO4 does not alter uptake of As in C. riparius. The potential for movement of As to terrestrial systems exists, though trophic transfer may be more likely during the aquatic larval stage.

Arsenic Speciation, Distribution, and Bioaccessibility in Shrews and Their Food

Shrews (Sorex cinereus) collected at a historic mine in Nova Scotia, Canada, had approximately twice the arsenic body burden and 100 times greater daily intake of arsenic compared with shrews from a nearby uncontaminated background site. Shrews store arsenic as inorganic and simple methylated arsenicals. Much of the arsenic associated with their primary food source, i.e., small invertebrates, may be soil adsorbed to their exoskeletons. A physiologically based extraction test estimated that 47±2% of invertebrate arsenic is bioaccessible in the shrew gastrointestinal tract. Overall, shrews appear to be efficient at processing and excreting inorganic arsenic.

CADMIUM AND ARSENIC EXPOSURE FACTORS IN A POPULATION LIVING ON POLLUTED SOILS, CASSIOPÉE STUDY, AVEYRON, FRANCE, 2008

Background and Aims: The town of Viviez (south-west of France) experienced 150 years of industrial activity generating atmospheric emissions until 1987 and substantial soil pollution, in particular by cadmium and arsenic. A public health assessment was carried out in order to estimate the health impact of this pollution and to formulate recommendations. This assessment included an exposure study with the objective of identifying exposure factors that increase the cadmium and arsenic body burden. Methods: Adult residents of Viviez and Montbazens (an unexposed town) who did not have occupational exposure to pollutants were included. Urinary cadmium and arsenic were analyzed by multivariate regression taking into account individual factors (age, smoking…) and environmental factors. Statistical methods for analysis of censored data were used in order to take into account concentrations below detection limit. Results: In Viviez, 21.6% of adults exceeded 1 µg of cadmium/g.creatinine and 5% exceeded 2 µg/g.creatinine against 4% and 0% in Montbazens. After adjustment for individual factors, the geometric means of urinary cadmium and arsenic were higher in Viviez than in Montbazens. Contrary to Montbazens, some environmental factors in Viviez were associated with urinary cadmium (length of residence, consumption of local fruit and vegetables and animal products), and with urinary arsenic (recent consumption of local poultry, consumption of local well and spring water, low frequency of mopping the floor, frequency of gardening). Conclusions: Differences in mean concentrations between the exposed and the unexposed town and exposure factors associated with cadmium and arsenic body burden suggest an environmental exposure of Viviez population. Residents could be presently exposed by local food ingestion and by inhalation or ingestion of polluted dust and soils. They could also have been exposed in the past by inhalation of atmospheric emissions. Recommendations based on these results will be made to limit further exposure.

A Transgenic Drosophila Model for Arsenic Methylation Suggests a Metabolic Rationale for Differential Dose-Dependent Toxicity Endpoints

The mechanisms by which exposure to arsenic induces its myriad pathological effects are undoubtedly complex, while individual susceptibility to their type and severity is likely to be strongly influenced by genetic factors. Human metabolism of arsenic into methylated derivatives, once presumed to result in detoxification, may actually produce species with significantly greater pathological potential. We introduce a transgenic Drosophila model of arsenic methylation, allowing its consequences to be studied in a higher eukaryote exhibiting conservation of many genes and pathways with those of human cells while providing an important opportunity to uncover mechanistic details via the sophisticated genetic analysis for which the system is particularly well suited. The gene for the human enzyme, arsenic (+3 oxidation state) methyltransferase, was introduced into nonmethylating Drosophila under inducible control. Transgenic flies were characterized for enzyme inducibility, production of methylated arsenic species, and the dose-dependent consequences for chromosomal integrity and organismal longevity. Upon enzyme induction, transgenic flies processed arsenite into mono and dimethylated derivatives identical to those found in human urine. When induced flies were exposed to 9 ppm arsenite, chromosomal stability was clearly reduced, whereas at much higher doses, adult life span was significantly increased, a seemingly paradoxical pair of outcomes. Measurement of arsenic body burden in the presence or absence of methylation suggested that enhanced clearance of methylated species might explain this greater longevity under acutely toxic conditions. Our study clearly demonstrates both the hazards and the benefits of arsenic methylation in vivo and suggests a resolution based on evolutionary grounds.

Arsenic (+ 3 oxidation state) methyltransferase genotype affects steady-state distribution and clearance of arsenic in arsenate-treated mice

Arsenic (+ 3 oxidation state) methyltransferase ( As3mt) catalyzes formation of mono-, di-, and tri-methylated metabolites of inorganic arsenic. Distribution and retention of arsenic were compared in adult female As3mt knockout mice and wild-type C57BL/6 mice using a regimen in which mice received daily oral doses of 0.5 mg of arsenic as arsenate per kilogram of body weight. Regardless of genotype, arsenic body burdens attained steady state after 10 daily doses. At steady state, arsenic body burdens in As3mt knockout mice were 16 to 20 times greater than in wild-type mice. During the post dosing clearance period, arsenic body burdens declined in As3mt knockout mice to ~ 35% and in wild-type mice to ~ 10% of steady-state levels. Urinary concentration of arsenic was significantly lower in As3mt knockout mice than in wild-type mice. At steady state, As3mt knockout mice had significantly higher fractions of the body burden of arsenic in liver, kidney, and urinary bladder than did wild-type mice. These organs and lung had significantly higher arsenic concentrations than did corresponding organs from wild-type mice. Inorganic arsenic was the predominant species in tissues of As3mt knockout mice; tissues from wild-type mice contained mixtures of inorganic arsenic and its methylated metabolites. Diminished capacity for arsenic methylation in As3mt knockout mice prolongs retention of inorganic arsenic in tissues and affects whole body clearance of arsenic. Altered retention and tissue tropism of arsenic in As3mt knockout mice could affect the toxic or carcinogenic effects associated with exposure to this metalloid or its methylated metabolites.

Ecosystem Perspective of Groundwater Arsenic Contamination in India and Relevance in Policy

Millions of people living in India are at risk by consuming arsenic contaminated groundwater. Several technological solutions have failed to address the problem due to segmental approaches, resulting in human suffering for a period of three decades. The article is based on an analysis of arsenic-related health problems from an ecosystem perspective through a primary survey conducted in five arsenic affected villages in the state of West Bengal and review of existing research and policy documents. Although modern agricultural practices and drinking water policies have resulted in arsenic contamination of groundwater, current mitigation policy is essentially confined to biomedical approaches, which includes potable water supply and medical care. The study also shows that existing disparity, difficulty in coping, inaccessibility to health service and potable water supply and lack of participation in decision making have resulted in more suffering among the poor. On the other hand, spreading of arsenic contamination in the ecosystem remains unabated. Foods grown in the affected area have emerged as additional sources of exposure to humans. There is lack of evidence of any perceivable benefits due to sustainable agriculture, as present nature of agriculture practice is essentially driven by crop yield only. Further research is needed to generate credible evidence of alternative agriculture paradigms that may eventually reduce body burden of arsenic through reduced dependency on groundwater.

Predicting bioavailability and bioaccumulation of arsenic by freshwater clam Corbicula fluminea using valve daily activity

There are many bioindicators. However, it remains largely unknown which metal-bioindicator systems will give the reasonable detection ranges of bioavailable metals in the aquatic ecosystem. Various experimental data make the demonstration of biomonitoring processes challenging. Ingested inorganic arsenic is strongly associated with a wide spectrum of adverse health outcomes. Freshwater clam Corbicula fluminea, one of the most commonly used freshwater biomomitoring organisms, presents daily activity in valve movement and demonstrates biotic uptake potential to accumulate arsenic. Here, a systematical way was provided to dynamically link valve daily activity in C. fluminea and arsenic bioavailability and toxicokinetics to predict affinity at arsenic-binding site in gills and arsenic body burden. Using computational ecotoxicology methods, a valve daily rhythm model can be tuned mathematically to the responsive ranges of valve daily activity system in response to varied bioavailable arsenic concentration. The patterned response then can be used to predict the site-specific bioavailable arsenic concentration at the specific measuring time window. This approach can yield predictive data of results from toxicity studies of specific bioindicators that can assist in prediction of risk for aquatic animals and humans.

Effect of Spirulina on Toxic Signs, Body Weight and Hematological Parameters in Arsenic Induced Toxicities in Ducks

The present study, was undertaken for the effect of spirulina on toxic signs, body weight and hematological parameters in arsenic induced toxicities in ducks. One hundred and 75 ducklings were divided into 5 equal groups separately. One group (T ) of ducklings was kept as control. One group (T ) of 0 1 ducklings were given arsenic trioxide @ 100 mg/L drinking water and rest three groups of ducklings (T , T 2 3 and T ) were given arsenic trioxide @ 100 mg/L plus spirulina in three different doses i.e. 30, 60 and 120 4 mg/L in drinking water daily for 90 days starting from day 15. Five birds were sacrificed from each group in every 15 day intervals and toxic signs, body weight and hematological parameters were recorded. Ducks of T group (only arsenic trioxide) showed depression, reduced feed intake, dullness and ruffled feathers which 1 were in mild in nature in other groups i.e. arsenic plus spirulina. In arsenic treated groups (T ) the not gained 1 body weight was maximum (14.93%), whereas in arsenic plus spirulina treated groups (T T and T ) the not 2, 3 4 gained body weight in ducks (4.08-11.26%) were better than only arsenic treated groups. Reduction of TEC, Hb and PCV values and rise of ESR values were significant (P<0.01) in T (arsenic treated) groups. However, 1 in arsenic plus spirulina treated rest groups reduction of TEC, Hb and PCV were less than arsenic treated groups. The present study reveals that spirulina may be helpful for reducing the body burden of arsenic in ducks.

A Body-Weight-Based Method to Estimate Inorganic Arsenic Body Burden Through Tilapia Consumption in Taiwan

In the present study, a stage-classified exposure model is developed to better characterize long-term arsenic (As) accumulation of both genders of children, adolescents, and adults through tilapia consumption in Taiwan. Ingestion rate as well as elimination rate of As are treated dynamically and are used to parameterize the stage-classified accumulation model. Model simulations are carried out to produce temporal changes of As body burden of the residents who consume tilapia from blackfoot disease (BFD)-endemic area in three major cities in Taiwan. The model presented here can be served as a strong framework for refining human health risk assessments through fish consumption.